diff --git a/include/ir/IR.h b/include/ir/IR.h
index 3cc880e..75ce986 100644
--- a/include/ir/IR.h
+++ b/include/ir/IR.h
@@ -412,6 +412,15 @@ class BasicBlock : public Value {
     return ptr;
   }
 
+  template <typename T, typename... Args>
+  T* Prepend(Args&&... args) {
+    auto inst = std::make_unique<T>(std::forward<Args>(args)...);
+    auto* ptr = inst.get();
+    ptr->SetParent(this);
+    instructions_.insert(instructions_.begin(), std::move(inst));
+    return ptr;
+  }
+
  private:
   Function* parent_ = nullptr;
   std::vector<std::unique_ptr<Instruction>> instructions_;
diff --git a/include/irgen/IRGen.h b/include/irgen/IRGen.h
index a18ff6a..abd8a25 100644
--- a/include/irgen/IRGen.h
+++ b/include/irgen/IRGen.h
@@ -58,6 +58,8 @@ class IRGenImpl final : public SysYBaseVisitor {
   std::shared_ptr<ir::Type> ToIRType(const TypeDesc& ty);
   std::shared_ptr<ir::Type> ToIRParamType(const TypeDesc& ty);
   ir::Value* DefaultValue(const TypeDesc& ty);
+  ir::AllocaInst* CreateEntryAlloca(std::shared_ptr<ir::Type> ty,
+                                    const std::string& name);
   void InitArray(ir::Value* base_ptr, const TypeDesc& ty,
                  SysYParser::InitValContext* init);
   void InitConstArray(ir::Value* base_ptr, const TypeDesc& ty,
diff --git a/scripts/run_lab2.sh b/scripts/run_lab2.sh
index c4adf45..4d1d351 100644
--- a/scripts/run_lab2.sh
+++ b/scripts/run_lab2.sh
@@ -13,7 +13,7 @@ mkdir -p "$(dirname \"$RESULT_FILE\")"
 
 	cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DCOMPILER_PARSE_ONLY=OFF
 	cmake --build build -j "$(nproc)"
-	bash scripts/test_lab2.sh
+	CASE_DIR=test/test_case bash scripts/test_lab2.sh
 
 	echo "[run_lab2] end: $(date '+%Y-%m-%d %H:%M:%S')"
 } 2>&1 | tee "$RESULT_FILE"
diff --git a/scripts/test_lab2.sh b/scripts/test_lab2.sh
index 5d6c8a3..91d831b 100644
--- a/scripts/test_lab2.sh
+++ b/scripts/test_lab2.sh
@@ -65,7 +65,13 @@ echo "cases    : $CASE_DIR" | tee -a "$LOG_FILE"
 echo "out dir  : $OUT_DIR" | tee -a "$LOG_FILE"
 
 echo "[Step 1] single sample check: simple_add.sy" | tee -a "$LOG_FILE"
-if "$VERIFY_SCRIPT" "$CASE_DIR/simple_add.sy" "$OUT_DIR" --run >> "$LOG_FILE" 2>&1; then
+sample_input="$(find "$CASE_DIR" -type f -name "simple_add.sy" -print -quit)"
+if [[ -z "$sample_input" ]]; then
+  echo "single sample: FAIL (simple_add.sy not found under $CASE_DIR)" | tee -a "$LOG_FILE"
+  echo "stop here. see log: $LOG_FILE" >&2
+  exit 1
+fi
+if "$VERIFY_SCRIPT" "$sample_input" "$OUT_DIR" --run >> "$LOG_FILE" 2>&1; then
   echo "single sample: PASS" | tee -a "$LOG_FILE"
 else
   echo "single sample: FAIL" | tee -a "$LOG_FILE"
diff --git a/src/irgen/IRGenDecl.cpp b/src/irgen/IRGenDecl.cpp
index afa3156..c706771 100644
--- a/src/irgen/IRGenDecl.cpp
+++ b/src/irgen/IRGenDecl.cpp
@@ -108,7 +108,7 @@ std::any IRGenImpl::visitVarDef(SysYParser::VarDefContext* ctx) {
   if (!ty) {
     throw std::runtime_error(FormatError("irgen", "变量类型缺失"));
   }
-  auto* slot = builder_.CreateAlloca(ToIRType(*ty), module_.GetContext().NextTemp());
+  auto* slot = CreateEntryAlloca(ToIRType(*ty), module_.GetContext().NextTemp());
   var_storage_[ctx] = slot;
 
   if (ty->dims.empty()) {
@@ -181,7 +181,7 @@ std::any IRGenImpl::visitConstDef(SysYParser::ConstDefContext* ctx) {
   if (!ty) {
     throw std::runtime_error(FormatError("irgen", "常量类型缺失"));
   }
-  auto* slot = builder_.CreateAlloca(ToIRType(*ty), module_.GetContext().NextTemp());
+  auto* slot = CreateEntryAlloca(ToIRType(*ty), module_.GetContext().NextTemp());
   const_storage_[ctx] = slot;
 
   if (ty->dims.empty()) {
diff --git a/src/irgen/IRGenExp.cpp b/src/irgen/IRGenExp.cpp
index 37d338f..4001137 100644
--- a/src/irgen/IRGenExp.cpp
+++ b/src/irgen/IRGenExp.cpp
@@ -122,54 +122,54 @@ std::any IRGenImpl::visitUnaryExp(SysYParser::UnaryExpContext* ctx) {
     for (size_t i = 0; i < args.size() && i < param_tys.size(); ++i) {
       auto* arg = args[i];
       const auto& pty = param_tys[i];
-      if (pty->IsPointer() && arg && arg->GetType() && arg->GetType()->IsPointer()) {
-        bool param_elem_array = pty->GetElementType()->IsArray();
-        bool arg_elem_array = arg->GetType()->GetElementType()->IsArray();
-        if (!param_elem_array && arg_elem_array) {
-          std::vector<ir::Value*> idx = {builder_.CreateConstInt(0),
-                                         builder_.CreateConstInt(0)};
-          args[i] = builder_.CreateGep(arg, std::move(idx),
-                                       module_.GetContext().NextTemp());
-          arg = args[i];
-        } else if (param_elem_array && arg_elem_array) {
-          auto* param_elem = pty->GetElementType().get();
-          auto* arg_elem = arg->GetType()->GetElementType().get();
-          if (param_elem && arg_elem && arg_elem->IsArray() &&
-              arg_elem->GetElementType()->Equals(*param_elem)) {
-            std::vector<ir::Value*> idx = {builder_.CreateConstInt(0)};
+      if (pty->IsPointer()) {
+        if (arg && arg->GetType() && arg->GetType()->IsPointer()) {
+          bool param_elem_array = pty->GetElementType()->IsArray();
+          bool arg_elem_array = arg->GetType()->GetElementType()->IsArray();
+          if (!param_elem_array && arg_elem_array) {
+            std::vector<ir::Value*> idx = {builder_.CreateConstInt(0),
+                                           builder_.CreateConstInt(0)};
             args[i] = builder_.CreateGep(arg, std::move(idx),
                                          module_.GetContext().NextTemp());
             arg = args[i];
+          } else if (param_elem_array && arg_elem_array) {
+            auto* param_elem = pty->GetElementType().get();
+            auto* arg_elem = arg->GetType()->GetElementType().get();
+            if (param_elem && arg_elem && arg_elem->IsArray() &&
+                arg_elem->GetElementType()->Equals(*param_elem)) {
+              std::vector<ir::Value*> idx = {builder_.CreateConstInt(0)};
+              args[i] = builder_.CreateGep(arg, std::move(idx),
+                                           module_.GetContext().NextTemp());
+              arg = args[i];
+            }
+          } else if (param_elem_array && !arg_elem_array) {
+            if (auto* gep = dynamic_cast<ir::GepInst*>(arg)) {
+              const auto& idx = gep->GetIndices();
+              auto is_zero = [](ir::Value* v) {
+                auto* ci = dynamic_cast<ir::ConstantInt*>(v);
+                return ci && ci->GetValue() == 0;
+              };
+              if (idx.size() == 2 && is_zero(idx[0]) && is_zero(idx[1])) {
+                auto* base = gep->GetBasePtr();
+                if (base && base->GetType() && base->GetType()->IsPointer() &&
+                    base->GetType()->GetElementType()->IsArray()) {
+                  args[i] = base;
+                  arg = base;
+                }
+              }
+            }
           }
-        } else if (param_elem_array && !arg_elem_array) {
-          if (auto* gep = dynamic_cast<ir::GepInst*>(arg)) {
-            const auto& idx = gep->GetIndices();
-            auto is_zero = [](ir::Value* v) {
-              auto* ci = dynamic_cast<ir::ConstantInt*>(v);
-              return ci && ci->GetValue() == 0;
-            };
-            if (idx.size() == 2 && is_zero(idx[0]) && is_zero(idx[1])) {
-              auto* base = gep->GetBasePtr();
-              if (base && base->GetType() && base->GetType()->IsPointer() &&
-                  base->GetType()->GetElementType()->IsArray()) {
+        } else if (arg && arg->GetType() && arg->GetType()->IsInt32()) {
+          if (auto* load = dynamic_cast<ir::LoadInst*>(arg)) {
+            auto* base = load->GetPtr();
+            if (base && base->GetType() && base->GetType()->IsPointer()) {
+              auto* elem = base->GetType()->GetElementType().get();
+              if (elem && elem->IsPointer() &&
+                  elem->GetElementType()->Equals(*pty->GetElementType())) {
                 args[i] = base;
                 arg = base;
               }
             }
-          } else if (auto* gep = dynamic_cast<ir::GepInst*>(arg)) {
-            auto* base = gep->GetBasePtr();
-            if (base && base->GetType() && base->GetType()->IsPointer() &&
-                base->GetType()->GetElementType()->IsArray()) {
-              auto* base_elem = base->GetType()->GetElementType().get();
-              auto* param_elem = pty->GetElementType().get();
-              if (base_elem && base_elem->IsArray() && param_elem &&
-                  base_elem->GetElementType()->Equals(*param_elem)) {
-                std::vector<ir::Value*> idx2 = {builder_.CreateConstInt(0)};
-                args[i] = builder_.CreateGep(base, std::move(idx2),
-                                             module_.GetContext().NextTemp());
-                arg = args[i];
-              }
-            }
           }
         }
       }
@@ -329,8 +329,11 @@ std::any IRGenImpl::visitLVal(SysYParser::LValContext* ctx) {
     throw std::runtime_error(FormatError("irgen", "无法解析左值类型"));
   }
   bool as_rvalue = true;
-  if (!ty->dims.empty() && ctx->LBRACK().empty()) {
-    as_rvalue = false;
+  if (!ty->dims.empty()) {
+    const size_t index_count = ctx->exp().size();
+    if (index_count == 0 || index_count < ty->dims.size()) {
+      as_rvalue = false;
+    }
   }
   return static_cast<ir::Value*>(LoadIfNeeded(addr, *ty, as_rvalue));
 }
@@ -648,6 +651,18 @@ ir::Value* IRGenImpl::DefaultValue(const TypeDesc& ty) {
   return builder_.CreateConstInt(0);
 }
 
+ir::AllocaInst* IRGenImpl::CreateEntryAlloca(std::shared_ptr<ir::Type> ty,
+                                             const std::string& name) {
+  if (!func_) {
+    throw std::runtime_error(FormatError("irgen", "CreateEntryAlloca 缺少函数"));
+  }
+  auto* entry = func_->GetEntry();
+  if (!entry) {
+    throw std::runtime_error(FormatError("irgen", "CreateEntryAlloca 缺少入口块"));
+  }
+  return entry->Prepend<ir::AllocaInst>(std::move(ty), name);
+}
+
 size_t IRGenImpl::ArrayStride(const TypeDesc& ty, size_t dim) const {
   size_t stride = 1;
   for (size_t i = dim + 1; i < ty.dims.size(); ++i) {
@@ -749,10 +764,14 @@ void IRGenImpl::InitArray(ir::Value* base_ptr, const TypeDesc& ty,
     ir::Value* addr = builder_.CreateGep(base_ptr, std::move(indices),
                                          module_.GetContext().NextTemp());
     ir::Value* value = values[idx];
-    if (ty.base == BaseTypeKind::Float && (value->IsInt1() || value->IsInt32())) {
-      value = CastToFloat(value);
+    if (ty.base == BaseTypeKind::Float) {
+      if (value->IsInt1() || value->IsInt32()) {
+        value = CastToFloat(value->IsInt1() ? CastToInt(value) : value);
+      }
     } else if (ty.base == BaseTypeKind::Int && value->IsFloat()) {
       value = CastToInt(value);
+    } else if (ty.base == BaseTypeKind::Int && value->IsInt1()) {
+      value = CastToInt(value);
     }
     builder_.CreateStore(value, addr);
   }
@@ -777,10 +796,14 @@ void IRGenImpl::InitConstArray(ir::Value* base_ptr, const TypeDesc& ty,
     ir::Value* addr = builder_.CreateGep(base_ptr, std::move(indices),
                                          module_.GetContext().NextTemp());
     ir::Value* value = values[idx];
-    if (ty.base == BaseTypeKind::Float && (value->IsInt1() || value->IsInt32())) {
-      value = CastToFloat(value);
+    if (ty.base == BaseTypeKind::Float) {
+      if (value->IsInt1() || value->IsInt32()) {
+        value = CastToFloat(value->IsInt1() ? CastToInt(value) : value);
+      }
     } else if (ty.base == BaseTypeKind::Int && value->IsFloat()) {
       value = CastToInt(value);
+    } else if (ty.base == BaseTypeKind::Int && value->IsInt1()) {
+      value = CastToInt(value);
     }
     builder_.CreateStore(value, addr);
   }
diff --git a/src/irgen/IRGenFunc.cpp b/src/irgen/IRGenFunc.cpp
index 60c0b68..bbd071e 100644
--- a/src/irgen/IRGenFunc.cpp
+++ b/src/irgen/IRGenFunc.cpp
@@ -62,6 +62,8 @@ std::any IRGenImpl::visitCompUnit(SysYParser::CompUnitContext* ctx) {
   declare_builtin("putfloat", ir::Type::GetVoidType(), {f32});
   declare_builtin("putfarray", ir::Type::GetVoidType(),
                   {i32, ir::Type::GetPointerType(f32)});
+  declare_builtin("starttime", ir::Type::GetVoidType(), {});
+  declare_builtin("stoptime", ir::Type::GetVoidType(), {});
 
   for (auto* funcDef : ctx->funcDef()) {
     if (funcDef) funcDef->accept(this);
@@ -98,8 +100,8 @@ std::any IRGenImpl::visitFuncDef(SysYParser::FuncDefContext* ctx) {
       if (!pty) {
         throw std::runtime_error(FormatError("irgen", "缺少参数类型"));
       }
-      auto slot = builder_.CreateAlloca(ToIRParamType(*pty),
-                                        module_.GetContext().NextTemp());
+      auto slot = CreateEntryAlloca(ToIRParamType(*pty),
+                module_.GetContext().NextTemp());
       builder_.CreateStore(arg, slot);
       param_storage_[param_ctx] = slot;
     }
diff --git a/src/irgen/IRGenStmt.cpp b/src/irgen/IRGenStmt.cpp
index 80c4816..1aac9a9 100644
--- a/src/irgen/IRGenStmt.cpp
+++ b/src/irgen/IRGenStmt.cpp
@@ -68,10 +68,18 @@ std::any IRGenImpl::visitStmt(SysYParser::StmtContext* ctx) {
     if (!ty) {
       throw std::runtime_error(FormatError("irgen", "无法解析赋值类型"));
     }
-    if (ty->base == BaseTypeKind::Float && val->IsInt32()) {
-      val = CastToFloat(val);
-    } else if (ty->base == BaseTypeKind::Int && val->IsFloat()) {
-      val = CastToInt(val);
+    if (ty->base == BaseTypeKind::Float) {
+      if (val->IsInt1()) {
+        val = CastToFloat(CastToInt(val));
+      } else if (val->IsInt32()) {
+        val = CastToFloat(val);
+      }
+    } else if (ty->base == BaseTypeKind::Int) {
+      if (val->IsFloat()) {
+        val = CastToInt(val);
+      } else if (val->IsInt1()) {
+        val = CastToInt(val);
+      }
     }
     builder_.CreateStore(val, addr);
     return BlockFlow::Continue;
diff --git a/src/sem/Sema.cpp b/src/sem/Sema.cpp
index f135a5b..9ac563a 100644
--- a/src/sem/Sema.cpp
+++ b/src/sem/Sema.cpp
@@ -495,7 +495,8 @@ class SemaVisitor final : public SysYBaseVisitor {
   std::unordered_map<std::string, SysYParser::FuncDefContext*> func_table_;
   const std::unordered_set<std::string> builtin_funcs_ = {
       "getint", "getch", "getarray", "putint", "putch", "putarray",
-      "getfloat", "getfarray", "putfloat", "putfarray"};
+      "getfloat", "getfarray", "putfloat", "putfarray", "starttime",
+      "stoptime"};
   BaseTypeKind current_ret_ = BaseTypeKind::Void;
   bool seen_return_ = false;
   int loop_depth_ = 0;
diff --git a/sylib/sylib.c b/sylib/sylib.c
index d968ce0..1b357a5 100644
--- a/sylib/sylib.c
+++ b/sylib/sylib.c
@@ -22,10 +22,11 @@ void putint(int x) { printf("%d", x); }
 void putch(int x) { putchar(x); }
 
 void putarray(int n, int a[]) {
-	printf("%d", n);
+	printf("%d:", n);
 	for (int i = 0; i < n; ++i) {
 		printf(" %d", a[i]);
 	}
+	printf("\n");
 }
 
 float getfloat() {
@@ -50,5 +51,11 @@ void putfarray(int n, float a[]) {
 	for (int i = 0; i < n; ++i) {
 		printf(" %a", a[i]);
 	}
+	printf("\n");
 }
 
+// Performance timing hooks (no-op stubs for correctness testing).
+void starttime() {}
+
+void stoptime() {}
+